HDD Unmounts itself - Disk Full Error

Anyone have issues with HDD unmounting by itself? I've tried to different sata drives and its happened on both. Set up as ext4 and they work fine for recordings then out of the blue I'll get a disk full error despite having 600gb free! If I check it then in device manager is says unavailable. I've attached last error log when I try to remount. This is getting very frustrating as is keeps happening.

Yes it's an internal 2.5 sata drive I have. Seeing as I've had issues with 2 different ones you could be right that maybe the cable is the issue. Thanks for that I'll try replacing it and see how it goes